Merge pull request #10718 from ethereum/gitignoreClion

Extend .gitignore to all CLion build directories and allow "build" to be a symlink.

.gitignore

@@ -31,8 +31,7 @@ prerelease.txt
 *.app
 
 # Build directory
-build/
-/build*/
+/build*
 emscripten_build/
 docs/_build
 __pycache__
@@ -40,7 +39,7 @@ docs/utils/*.pyc
 /deps/downloads/
 deps/install
 deps/cache
-cmake-build-debug/
+cmake-build-*/
 
 # vim stuff
 [._]*.sw[a-p]